As the most important communication tool, email is extensively used in the business environment. In many cases, the email is chosen as a discussion tool, in which different users input their own contents and comments to each other. When a user receives an email of a discussion with a long history, it is difficult for him to identify who input what. In general, some users may choose different colors to represent themselves and then to differentiate the contents input by them. But this raises many redundant repetitive operations and it is error prone. On the other hand, when the discussions occur many times, it is difficult to extract the contents input by a specific user even if the contents have different styles. The existing email clients will add a special symbol at the beginning of each line when the user replies to the others' emails. But the symbol may be corrupted by reformatting the email contents. Some advanced email clients, such as Lotus Notes, use extensible format to treat the cited contents in email as a whole element. But when the users want to freely insert their own comments between the cited contents, those comments break the original element structure and the same problem occurs.
An international application of WO2005/098701A2 published on Oct. 20, 2005 and entitled “Displaying Conversations In a Conversation-Based Email System” describes a conversation-based email system which attempts to resolve the problem mentioned above.
This application proposes a complete email system supporting discussions, in which a user can manually tag the email contents to classify and organize. The system provides an effective visual presentation and related search for locating these tags in accordance with discussion threads. The core implemented by this system is a “conversation engine”, through which the problem of associating different email contents with discussion threads is resolved. However, this system needs support of a server side such as conversation engines; and the method for resolving the above-mentioned problems is to tag the header of the email, mainly relating to effective presentation of incorporating a plurality of associated emails, which does not match natural convention of the current users to use email systems, thereby bringing some inconvenience to the users of email.